Low-pressure discharge lamp driving circuit

Abstract

A driving circuit for a low-pressure discharge lamp, particularly a compact fluorescent lamp, features a heating transformer with two separate secondary windings, which are respectively permanently connected to the lamp electrodes, and furnish them with pre-heating current. Parallel to the primary winding of the transformer, there is connected a series circuit of an operating switch, a ballast inductor, and the discharge path formed between the lamp electrodes. The electrodes are connected to each other via a starter connected in parallel to the discharge path.

I claim: 
     
       1. A driving circuit for a low-pressure discharge lamp adapted for use in photo-polymerization with two pre-heatable electrodes (11,12) each directly connected to a secondary winding (9,10) of a heating transformer (4), said heating transformer having a primary winding (3) connected for power supply purposes through a power switch means (7,8) to an AC voltage source, wherein, there is provided, parallel to the primary winding (3), a series circuit of a ballast inductor (15), and a discharge path formed between said electrodes (11,12), and   said electrodes (11,12) are connected to each other by a starter device (18) connected in parallel to said discharge path, and wherein   an operating switch (14) is provided, connected in series with said ballast inductor (15), and adapted to switch ON and OFF discharge current of said lamp (13), thereby completely suppressing radiation generation during a readiness operating state.   
     
     
       2. The driving circuit of claim 1, wherein said starter device is a glow lamp (18).   
     
     
       3. The driving circuit of claim 1, wherein said operating switch (14) is a controllable switch having a control signal input.   
     
     
       4. The driving circuit of claim 2, wherein said operating switch (14) is a controllable switch having a control signal input.